1. Field of the Invention
The present invention relates to an adapter attached to the back of a camera body (which was designed for use with an ordinary silver halide film) in place of the back cover of the camera to enable video pictures to be stored on a magnetic disk.
2. Description of the Prior Art
Up to now, there have been proposed still video cameras which were designed specifically for picture taking on a magnetic disk. Such video cameras usually have an image pick-up device located at the focal plane of the camera in the rear of the objective lens, and a deck portion at the back thereof to receive a magnetic disk.
However, such an arrangement of the video camera is inconvenient if it is to be employed in an adapter, as intended in this invention. The image pick-up plane of the still video camera cannot have a large size because of its high cost per area. Accordingly, cameras for use with a silver halide film have a larger picture frame size (i.e. the size of the frame of the film) than the image pick-up plane of the still video cameras. The still video cameras are designed with a flange-back adapted for such an image pick-up plane, and have a large depth dimension (from back to front).
Thus, the depth dimension will be extremely large if a still camera is coupled (in place of the rear cover) with a still video adapter constructed for a conventional still video camera, wherein the image pick-up device is located on the focal plane in the rear of the objective lens and the deck portion which receives the magnetic disk is located in the rear of the image pick-up device, because the depth dimension of the adapter is added to the depth dimension of the camera body.
Additionally, if a small image pick-up plane is located in the image plane of the camera for use with silver halide film, the angle of view will be too small. Accordingly, it is necessary for a still video adapter to have the image pick-up plane located out of the image plane of the camera, with the light from the object being photographed being transmitted through a optical relay system to the image pick-up plane, resulting in further bulkiness in the image pick-up device and also the entire body.